Display element, display device, and electronic device

ABSTRACT

A display element includes a light-emitting unit of a current drive type, and a drive unit that drives the light-emitting unit, in which the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow through the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit, the drive transistor and the write transistor are formed in a state of being separated by an element isolation region, on a semiconductor substrate, and a capacitance generated in a portion where the drive transistor and the write transistor face each other through the element isolation region functions as at least a part of the capacitance unit.

CROSS REFERENCES TO RELATED APPLICATIONS

The present Application is a Continuation Application of U.S. patentapplication Ser. No. 16/647,841 filed Mar. 16, 2020, which is a 371National Stage Entry of International Application No. PCT/JP2018/031892,filed on Aug. 29, 2018, which in turn claims priority from JapaneseApplication No. 2017-182677, filed on Sep. 22, 2017, the entire contentsof which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a display element, a display device,and an electronic device. More specifically, the present disclosurerelates to a display element used for a micro-display that requires apixel pitch in units of micrometers, a display device including thedisplay element, and an electronic device including the display device.

BACKGROUND ART

A display element is known including a light-emitting unit of a currentdrive type, and a display device is known including the display element.For example, a display element including a light-emitting unit includingan organic electroluminescence element has been attracting attention asa display element capable of high luminance light emission by lowvoltage direct current drive. Then, a display device including theorganic electroluminescence element is used not only in a direct-viewdisplay, but also in a micro-display that requires a pixel pitch inunits of micrometers.

To realize a pixel pitch in units of micrometers, a drive unit thatdrives the light-emitting unit of the current drive type is formed on asemiconductor substrate (see, for example, Patent Document 1). The driveunit includes a plurality of transistors and the like. Thus, to separateadjacent transistors, an element isolation region is required betweenthe transistors. In such an application, a so-called shallow trenchisolation (STI) method is preferable capable of forming the elementisolation region more finely than a local oxidation of silicon (LOCOS)method.

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2014-98779

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

As the pixel pitch becomes finer, the distance becomes narrower betweenthe transistors facing each other across the element isolation region.As a result, a capacitance increases generated between the transistorsfacing across the element isolation region. Then, it is conceivable thata burn-in phenomenon of a display image due to a change with time of thelight-emitting unit is emphasized by influence of the capacitance.

Thus, an object of the present disclosure is to provide a displayelement in which the capacitance generated between the transistors doesnot emphasize the burn-in phenomenon of the display image, a displaydevice including the display element, and an electronic device includingthe display device.

Solutions to Problems

A display element according to a first aspect of the present disclosurefor achieving the object described above is

a display element including

a light-emitting unit of a current drive type, and a drive unit thatdrives the light-emitting unit, in which

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

A display device according to the first aspect of the present disclosurefor achieving the object described above is

a display device including

display elements arrayed in a two-dimensional matrix, in which

the display elements each include a light-emitting unit of a currentdrive type, and a drive unit that drives the light-emitting unit,

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

An electronic device according to the first aspect of the presentdisclosure for achieving the object described above is

an electronic device including

a display device including display elements arrayed in a two-dimensionalmatrix, in which

the display elements each include a light-emitting unit of a currentdrive type, and a drive unit that drives the light-emitting unit,

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

Effects of the Invention

In the display element of the present disclosure, the drive unitincludes the drive transistor that causes the current corresponding tothe voltage held by the capacitance unit to flow through thelight-emitting unit, and the write transistor that writes the signalvoltage to the capacitance unit. Then, the capacitance generated in theportion where the drive transistor and the write transistor face eachother through the element isolation region functions as at least a partof the capacitance unit. As a result, it is possible to avoid that theburn-in phenomenon due to influence of the change with time of thevoltage-current characteristic (V-I) characteristic of thelight-emitting unit of the current drive type is emphasized by theinfluence of the capacitance. Furthermore, the advantageous effectsdescribed in the present disclosure are examples, and are not limited tothem and may include additional effects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a conceptual diagram of a display device according to a firstembodiment.

FIG. 2 is an equivalent circuit diagram of a display element including alight-emitting unit and a drive unit that drives the light-emittingunit.

FIG. 3 is a schematic partial cross-sectional view of a portionincluding the display element in a display area.

FIG. 4 is a schematic plan view for explaining an arrangement oftransistors in a drive unit according to the first embodiment.

FIG. 5 is a schematic cross-sectional view for explaining across-sectional structure of the transistors in the drive unit accordingto the first embodiment.

FIG. 6 is a schematic plan view for explaining an arrangement of thetransistors in a drive unit of a reference example.

FIG. 7 is a schematic cross-sectional view for explaining across-sectional structure of the transistors in the drive unit of thereference example.

FIG. 8 is a conceptual diagram of a display device including a displayelement including the drive unit of the reference example.

FIG. 9A is a schematic diagram for explaining a relationship between acurrent flowing through a light-emitting unit including an organicelectroluminescence element and a voltage between the anode electrodeand the cathode electrode of the light-emitting unit. FIG. 9B is aschematic graph for explaining a change with time of the voltage-currentcharacteristic (V-I) characteristic of the light-emitting unit.

FIG. 10A is a schematic circuit diagram for explaining a drain currentthat flows during light emission of the display element including thedrive unit of the reference example. FIG. 10B is a schematic graph forexplaining operation of the display element including the drive unit ofthe reference example.

FIG. 11 is an equivalent circuit diagram of a display element in thefirst embodiment.

FIG. 12 is a schematic plan view for explaining a shield wiring line inthe drive unit of the reference example.

FIG. 13 is a schematic plan view for explaining a shield wiring line inthe drive unit of the first embodiment.

FIG. 14 is a schematic cross-sectional view for explaining across-sectional structure of the transistors according to a firstmodification of the first embodiment.

FIG. 15 is a conceptual diagram of a display device according to asecond embodiment.

FIG. 16 is a schematic plan view for explaining an arrangement of thetransistors in a drive unit according to the second embodiment.

FIG. 17 is a conceptual diagram of a display device according to a thirdembodiment.

FIG. 18 is a schematic plan view for explaining an arrangement of thetransistors in a drive unit according to the third embodiment.

FIGS. 19A-B are external views of a lens interchangeable single lensreflex type digital still camera, and FIG. 19A illustrates a front viewof the camera and FIG. 19B illustrates a rear view of the camera.

FIG. 20 is an external view of a head mounted display.

FIG. 21 is an external view of a see-through head mounted display.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present disclosure will be described on the basis ofembodiments with reference to the drawings. The present disclosure isnot limited to the embodiments, and various numerical values andmaterials in the embodiments are examples. In the following description,the same reference signs will be used for the same elements or elementshaving the same function, and redundant description will be omitted.Note that, description will be given in the following order.

1. General description related to display element, display device, andelectronic device according to present disclosure

2. First embodiment

3. Second embodiment

4. Third embodiment

5. Description of electronic device and others

General Description Related to Display Element, Display Device, andElectronic Device According to Present Disclosure

As described above, a display element according to a first aspect of thepresent disclosure, and a display element used for a display deviceaccording to the first aspect of the present disclosure and anelectronic device according to the first aspect of the presentdisclosure (hereinafter, these may be simply referred to as “displayelements of the present disclosure”) each include

a light-emitting unit of a current drive type, and a drive unit thatdrives the light-emitting unit, in which

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

In the display element of the present disclosure,

a configuration can be made in which

the drive transistor and the write transistor are provided in a wellformed in the semiconductor substrate,

the drive transistor includes a first source/drain region to which afeeder line is connected and a second source/drain region connected toone end of the light-emitting unit,

the write transistor includes a first source/drain region to which thesignal voltage is supplied externally and a second source/drain regionconnected to a gate electrode of the drive transistor, and

the second source/drain region of the write transistor and the firstsource/drain region of the drive transistor are formed to face eachother through the element isolation region.

In the display element of the present disclosure including variouspreferable configurations described above, a configuration can be madein which the element isolation region is formed by a shallow trenchisolation (STI) structure in which an insulator is embedded in a groovedug in a surface of the semiconductor substrate.

In this case,

a configuration can be made in which

an impurity diffusion layer that forms a source/drain region of thedrive transistor and an impurity diffusion layer that forms asource/drain region of the write transistor are set to have a junctiondepth of greater than or equal to 1 micrometer.

In the display element of the present disclosure including variouspreferable configurations described above, a configuration can be madein which the drive transistor includes a p-channel field effecttransistor. In this case, the write transistor may have an n-channelconfiguration or a p-channel configuration. From a viewpoint ofstandardization of manufacturing processes, the conductivity type of thewrite transistor is preferably a p-channel field effect transistor thatis the same as that of the drive transistor.

In the display element of the present disclosure including variouspreferable configurations described above, a configuration can be madein which a shield wiring line is provided around a gate wiring line thatconnects the second source/drain region of the write transistor and thegate electrode of the drive transistor to each other. In this case, aconfiguration can be made in which the shield wiring line is connectedto the feeder line.

In the display element of the present disclosure including variouspreferable configurations described above, a configuration can be madein which the drive unit further includes another transistor. Aconfiguration can be made in which the drive unit further includes aswitching transistor connected between the feeder line and the firstsource/drain region of the drive transistor, or alternatively, the driveunit further includes a switching transistor connected between the oneend of the light-emitting unit and the second source/drain region of thedrive transistor.

As the light-emitting unit of the current drive type constituting thedisplay element of the present disclosure including the variouspreferable configurations described above, it is possible to use anorganic electroluminescence element, an LED element, a semiconductorlaser element, or the like. These elements can be configured using knownmaterials and methods. From a viewpoint of configuring a flat typedisplay device, it is preferable that a configuration is made in whichthe light-emitting unit includes an organic electroluminescence elementamong the elements.

Hereinafter, the display element, the display device, and the electronicdevice according to the present disclosure may be simply referred to asthe present disclosure.

A source driver and the like that drive the display device may beintegrated together on the semiconductor substrate on which the displayelements are arranged, or may be appropriately configured as a separatebody. These can be configured using known circuit elements. For example,a source driver, a power supply unit, and a vertical scanner illustratedin FIG. 1 can also be configured using known circuit elements. Inapplications where downsizing is required, such as a display device fora head mounted display or a viewfinder, it is preferable that thedisplay elements and the driver are formed on the same semiconductorsubstrate.

The display device may have a so-called monochrome display configurationor a color display configuration. In the case of a color displayconfiguration, a configuration can be made in which one pixel includes aplurality of subpixels, specifically, one pixel includes a set of a reddisplay element, a green display element, and a blue display element.Moreover, a configuration can also be made in which one set includesadditional one type or multiple types of display element together withthese three types of display elements.

As values of the pixels of the display device, in addition to U-XGA(1600, 1200), HD-TV (1920, 1080), and Q-XGA (2048, 1536), some of theimage display resolutions can be exemplified, such as (3840, 2160), and(7680, 4320); however, the values of the pixels of the display deviceare not limited to these values.

Various conditions described in the present specification are satisfiednot only in a case where the conditions mathematically strictly holdsbut also in a case where the conditions substantially holds. Presence ofvarious variations in design or manufacturing is allowed. Furthermore,each drawing used in the following description is schematic and does notindicate actual dimensions and ratios thereof. For example, FIG. 3described later illustrates a cross-sectional structure of the displaydevice, but does not indicate the ratio of width, height, thickness, andthe like. Furthermore, the shape of the waveform in the timing chartillustrated in, for example, FIG. 10 is also schematic.

First Embodiment

A first embodiment relates to a display element, a display device, andan electronic device according to the first aspect of the presentdisclosure.

FIG. 1 is a conceptual diagram of the display device according to thefirst embodiment.

First, an outline will be described of the display device with referenceto FIG. 1. A display device 1 includes display elements 70 arrayed in atwo-dimensional matrix. More specifically, the display elements 70 arearrayed in a two-dimensional matrix having a total of N×M elements, Nelements in the row direction and M elements in the column direction, ina state where each of the display elements 70 is connected to a scanningline WS1 and a feeder line (current supply line) PS1 extending in therow direction (X direction in FIG. 1), and a data line DTL extending inthe column direction (Y direction in FIG. 1).

The display elements 70 arrayed in a two-dimensional matrix form adisplay area 80 that displays an image. The number of rows of thedisplay elements 70 in the display area 80 is M, and the number of thedisplay elements 70 constituting the rows is N.

The number of the scanning lines WS1 and the number of the feeder linesPS1 are each M. The display elements 70 in the m-th row (where m=1, 2, .. . , M) are connected to the m-th scanning line WS1 _(m) and the m-thfeeder line PS1 _(m), and constitute one display element row.

Note that, the number of control lines DS1 illustrated in FIG. 15 andthe number of control lines EM1 illustrated in FIG. 17, described later,each are also M, and the m-th control line DS1 _(m) and control line EM1_(m) are connected to the display elements in the m-th row.

The number of the data lines DTL is N. The display elements 70 in then-th column (where n=1, 2, . . . , N) are connected to the n-th dataline DTL_(n).

Note that, although not illustrated in FIG. 1, the display device 1includes a common feeder line PS2 connected to all the display elements70 in common. For example, a ground potential is regularly supplied as acommon voltage to the common feeder line PS2.

The display device 1 includes a source driver 110 that drives thedisplay area 80, a power supply unit 120, and a vertical scanner 130.

The display area 80 is formed on a semiconductor substrate includingsilicon. Note that, the source driver 110, the power supply unit 120,and the vertical scanner 130 are also formed on a semiconductorsubstrate 100. That is, the display device 1 is a driver circuitintegrated display device.

A signal LD_(Sig) representing a gradation corresponding to an image tobe displayed is input to the source driver 110 from a device notillustrated, for example. The signal LD_(Sig) is, for example, a lowvoltage digital signal. The source driver 110 is used to generate ananalog signal corresponding to a gradation value of the video signalLD_(Sig) and supply the analog signal to the data line DTL as a videosignal. The analog signal to be generated is a signal having a peakvalue of about 10 volts, for example.

The vertical scanner 130 supplies a scanning signal to the scanning lineWS1. In accordance with the scanning signal, line-sequential scanning isperformed on the display elements 70 for each row. Corresponding toscanning of the scanning line WS1, the power supply unit 120 supplies apredetermined drive voltage to the feeder line PS1.

The display device 1 is, for example, a color display device, and agroup of three display elements 70 arranged in the row directionconstitutes one pixel. Thus, if N′=N/3, a total of N′×M pixels, N′pixels in the row direction and M pixels in the column direction, arearrayed in the display area 80.

As described above, line-sequential scanning is performed on the displayelements 70 for each row by the scanning signal of the vertical scanner130. The display element 70 located in the m-th row and the n-th columnis hereinafter referred to as the (n, m)-th display element 70.

In the display device 1, N display elements 70 arrayed in the m-th roware driven simultaneously. In other words, in the N display elements 70arranged along the row direction, timing of light emission/non-lightemission is controlled for each row to which the N display elements 70belong. If a display frame rate of the display device 1 is representedas FR (times/second), the scanning period per row (so-called horizontalscanning period) when the line-sequential scanning is performed on thedisplay device 1 for each row is less than (1/FR)×(1/M) seconds.

An outline of the display device 1 has been described above. Next,details of the display elements 70 will be described.

FIG. 2 is an equivalent circuit diagram of the display element includingthe light-emitting unit and the drive unit that drives thelight-emitting unit. Note that, for convenience of illustration, FIG. 2illustrates a connection relationship for one display element 70, morespecifically, the (n, m)-th display element 70.

The display element 70 includes a light-emitting unit ELP of the currentdrive type and a drive unit 71 that drives the light-emitting unit ELP.The drive unit 71 includes a capacitance unit C_(S), a drive transistorTR_(D) that causes a current corresponding to a voltage held by thecapacitance unit C_(S) to flow through the light-emitting unit ELP, anda write transistor TR_(W) that writes a signal voltage to thecapacitance unit C_(S).

The light-emitting unit ELP is a light-emitting unit of the currentdrive type whose light emission luminance changes depending on a valueof a current flowing, and specifically, includes an organicelectroluminescence element. The light-emitting unit ELP has knownconfiguration and structure including an anode electrode, a holetransporting layer, a light emitting layer, an electron transportinglayer, a cathode electrode, and the like.

The drive transistor TR_(D) includes a p-channel transistor.Furthermore, the write transistor TR_(W) also includes a p-channel fieldeffect transistor. Note that, the write transistor TR_(W) may be ann-channel field effect transistor.

The capacitance unit C_(S) is used to hold a voltage of the gateelectrode with respect to the source region of the drive transistorTR_(D) (so-called gate-source voltage). During light emission of thedisplay element 70, a first source/drain region (the side connected tothe feeder line PS1 in FIG. 2) of the drive transistor TR_(D) serves asthe source region, and a second source/drain region serves as the drainregion. A first electrode and a second electrode constituting thecapacitance unit C_(S) are connected to the first source/drain regionand the gate electrode of the drive transistor TR_(D), respectively. Thesecond source/drain region of the drive transistor TR_(D) is connectedto the anode electrode of the light-emitting unit ELP.

The write transistor TR_(W) has the gate electrode connected to thescanning line WS1, a first source/drain region connected to the dataline DTL, and a second source/drain region connected to the gateelectrode of the drive transistor TR_(D).

The other end (specifically, the cathode electrode) of thelight-emitting unit ELP is connected to the common feeder line PS2. Apredetermined voltage V_(Cath) is supplied to the common feeder linePS2. Note that, a capacitance of the light-emitting unit ELP isrepresented by a reference sign C_(EL). In a case where the capacitanceC_(EL) of the light-emitting unit ELP is small so that a trouble occursin driving the display element 70, for example, it is only required toprovide an auxiliary capacitance connected in parallel to thelight-emitting unit ELP as necessary.

When the write transistor TR_(W) is made to be in the conductive stateby the scanning signal from the vertical scanner 130 in a state wherethe voltage corresponding to the luminance of the image to be displayedon the data line DTL is supplied from the source driver 110, a voltagecorresponding to a gradation value of the image to be displayed iswritten to the capacitance unit C_(S). Then, the write transistor TR_(W)is made to be in the non-conductive state, a current flows through thedrive transistor TR_(D) depending on the voltage held in the capacitanceunit C_(S), and the light-emitting unit ELP emits light.

Here, the drive transistor TR_(D) is driven so that a drain currentI_(ds) flows in accordance with the following formula (1) in the lightemitting state of the light-emitting unit ELP. In the light emittingstate of the light-emitting unit ELP, the first source/drain region ofthe drive transistor TR_(D) serves as the source region, and the secondsource/drain region serves as the drain region. Note that,

parameters represent

μ: Effective mobility

L: Channel length

W: Channel width

V_(CC): Drive voltage supplied to source region

V_(Sig): Signal voltage applied to gate electrode

V_(th): Threshold voltage

C_(ox): (Relative dielectric constant of gate insulatinglayer)×(dielectric constant of vacuum)/(thickness of gate insulatinglayer)k≡(1/2)·(W/L)·C _(ox)I _(ds=k)·μ·((V _(CC) −V _(Sig))−|V _(th)|)²  (1)

Here, a three-dimensional arrangement relationship will be describedamong the light-emitting unit ELP, the transistor, and the like. FIG. 3is a schematic partial cross-sectional view of a portion including thedisplay element in the display area.

Each transistor constituting the display element 70 is formed, forexample, on a semiconductor substrate (reference numeral 100 illustratedin FIG. 1) in which a semiconductor layer 20 including silicon is formedon a base material 10. More specifically, the drive transistor TR_(D)and the write transistor TR_(W) are provided in an n well 21 formed inthe semiconductor layer 20. Note that, for convenience of illustration,only the drive transistor TR_(D) is illustrated in FIG. 3. Referencenumerals 23A and 23B denote a pair of source/drain regions of the drivetransistor TR_(D).

Each transistor is surrounded by an element isolation region 22. Areference numeral 32 denotes the gate electrode of the transistorTR_(D), and a reference numeral 31 denotes the gate insulating layer. Aswill be described later with reference to FIG. 4, the drive transistorTR_(D) and the write transistor TR_(W) are formed on the semiconductorsubstrate in a state of being separated by the element isolation region22. Note that, for convenience of illustration, in FIGS. 4, 5, 6, 7, 12,13, 14, 16, and 18 described later, the gate electrode is represented byreference numeral 31 regardless of the type of the transistor.

A second electrode 32′ constituting the capacitance unit C_(S) includesthe same material layer as the gate electrode 32, and is formed on aninsulating layer 31′ including the same material layer as the gateinsulating layer 31. An interlayer insulating layer 33 is formed on theentire surface of the semiconductor layer 20 including the gateelectrode 32 of the drive transistor TR_(D) and the electrode 32′. Theelectrode 32′ and an electrode 34 described later are arranged to faceeach other across the interlayer insulating layer 33.

The first source/drain region 23A of the drive transistor TR_(D) isconnected to the feeder line PS1 and the electrode 34 through a contacthole 35 provided in the interlayer insulating layer 33. Note that, theconnection portion is hidden and not visible in FIG. 3. On theinterlayer insulating layer 33, an interlayer insulating layer 40 isfurther formed.

On the interlayer insulating layer 40, the light-emitting unit ELP isprovided including an anode electrode 51, a hole transporting layer, alight emitting layer, an electron transporting layer, and a cathodeelectrode 53. Note that, in the drawing, the hole transporting layer,the light emitting layer, and the electron transporting layer arerepresented by a single layer 52. A second interlayer insulating layer54 is provided on a portion of the interlayer insulating layer 40 wherethe light-emitting unit ELP is not provided, a transparent substrate 60is arranged on the second interlayer insulating layer 54 and the cathodeelectrode 53, and light emitted from the light emitting layer passesthrough the substrate 60 and is emitted to the outside.

The anode electrode 51 and the second source/drain region 23B of thedrive transistor TR_(D) are connected through a contact hole 36 providedin the interlayer insulating layer 33, and the like. Note that, in FIG.3, the connection portion is hidden and not visible.

Furthermore, the cathode electrode 53 is connected to a wiring line 37(corresponding to the common feeder line PS2 to which the voltageV_(Cath) is supplied) provided on an extending portion of the interlayerinsulating layer 33 through contact holes 56 and 55 provided in thesecond interlayer insulating layer 54 and the interlayer insulatinglayer 40.

The three-dimensional arrangement relationship has been described aboveamong the light-emitting unit ELP, the transistor, and the like. Next,an arrangement will be described of the transistors in the drive unitaccording to the first embodiment.

FIG. 4 is a schematic plan view for explaining the arrangement of thetransistors in the drive unit according to the first embodiment. FIG. 5is a schematic cross-sectional view for explaining a cross-sectionalstructure of the transistors in the drive unit according to the firstembodiment.

As illustrated in FIGS. 4 and 5, the drive transistor TR_(D) and thewrite transistor TR_(W) are formed on the semiconductor substrate in astate of being separated by the element isolation region 22. Then, asecond source/drain region 23D of the write transistor TR_(W) and thefirst source/drain region 23A of the drive transistor TR_(D) are formedto face each other through the element isolation region 22. The elementisolation region 22 is formed by the shallow trench isolation (STI)structure in which the insulator is embedded in the groove dug in thesurface of the semiconductor substrate.

As described above, the drive transistor TR_(D) includes the firstsource/drain region 23A to which the feeder line PS1 is connected andthe second source/drain region 23B connected to one end of thelight-emitting unit ELP. Furthermore, the write transistor TR_(W)includes a first source/drain region 23C to which the signal voltage issupplied from the outside, and the second source/drain region 23Dconnected to the gate electrode of the drive transistor TR_(D).

As the pixel pitch becomes finer, the inter-terminal distance is reducedbetween the second source/drain region 23D of the write transistorTR_(W) and the second source/drain region 23A of the drive transistorTR_(D). As a result, a capacitance (parasitic capacitance) (representedby a reference sign C_(S1)) through the embedded insulator used as theelement isolation region 22 increases.

However, in the drive unit 71 of the present disclosure, the capacitancegenerated in a portion where the drive transistor TR_(D) and the writetransistor TR_(W) face each other through the element isolation region22 functions as at least a part of the capacitance unit. As will bedescribed in detail later with reference to FIG. 11, in thisconfiguration, the capacitance generated between the transistors doesnot emphasize the burn-in phenomenon of the display image.

Next, to help understanding of the present disclosure, an arrangement ofthe transistors and problems will be described in a drive unit of areference example in which the burn-in phenomenon is emphasized by thecapacitance generated between the transistors.

FIG. 6 is a schematic plan view for explaining the arrangement of thetransistors in the drive unit of the reference example. FIG. 7 is aschematic cross-sectional view for explaining a cross-sectionalstructure of the transistors in the drive unit of the reference example.

As is clear by comparing FIGS. 4 and 6, in the drive unit of thereference example (represented by a reference numeral 971 in FIG. 8described later), a connection relationship between the pair ofsource/drain regions 23A and 23B of the drive transistor TR_(D), and thefeeder line PS1 and the light-emitting unit ELP is opposite to that ofthe drive unit 71 of the first embodiment.

Also in this connection, a capacitance is generated in the portion wherethe drive transistor TR_(D) and the write transistor TR_(W) face eachother through the element isolation region 22. The capacitance isrepresented by a sign C_(GA).

FIG. 8 is a conceptual diagram of a display device including a displayelement including the drive unit of the reference example. Note that,for convenience of illustration, FIG. 8 illustrates a connectionrelationship for one display element 970 in a display device 9, morespecifically, the (n, m)-th display element 970.

As illustrated in FIG. 8, in the display element 970 including the driveunit 971 of the reference example, the capacitance C_(GA) functions as acapacitance connected between the gate electrode of the drive transistorTR_(D) and the anode electrode of the light-emitting unit ELP. As willbe described below, in this case, the luminance change due to a changewith time of the voltage-current characteristic (V-I) characteristic ofthe light-emitting unit ELP is further emphasized.

FIG. 9A is a schematic diagram for explaining a relationship between acurrent flowing through a light-emitting unit including an organicelectroluminescence element and a voltage between the anode electrodeand the cathode electrode of the light-emitting unit. FIG. 9B is aschematic graph for explaining the change with time of thevoltage-current characteristic (V-I) characteristic of thelight-emitting unit.

In general, the luminance of the light-emitting unit ELP including anorganic electroluminescence element is proportional to a currentflowing. Thus, basically, if a current I_(OLED) flowing through thelight-emitting unit ELP has the same value, the luminance of thelight-emitting unit ELP also has the same value. On the other hand, avoltage V_(OLED) between the terminals (between the anode electrode andthe cathode electrode) of the light-emitting unit ELP tends to graduallyincrease due to the change with time. Thus, as illustrated in FIG. 9B,the voltage-current characteristic (V-I) characteristic of thelight-emitting unit ELP changes from the initial state due to the changewith time.

As described above, if the current I_(OLED) flowing through thelight-emitting unit ELP has the same value, the luminance of thelight-emitting unit ELP basically has the same value. However, thevoltage V_(OLED) between the terminals of the light-emitting unit ELPgradually increases due to the change with time. Thus, if the voltagebetween the terminals of the light-emitting unit ELP in the initialstate corresponding to the current I_(OLED) is expressed asV_(OLED_INI), a voltage between the terminals of the light-emitting unitELP after the change with time can be represented asV_(OLED_INI)+V_(CWT).

In the drive unit 971 of the reference example, the gate voltage of thedrive transistor TR_(D) changes due to influence of the above-describedvoltage V_(CWT) due to the change with time, and the burn-in phenomenonis emphasized. Hereinafter, description will be given with reference toFIG. 10.

FIG. 10A is a schematic circuit diagram for explaining a drain currentthat flows during light emission of the display element including thedrive unit of the reference example. FIG. 10B is a schematic graph forexplaining operation of the display element including the drive unit ofthe reference example.

As illustrated in FIG. 10B, the write transistor TR_(W) enters theconductive state for a predetermined period by the scanning signalsupplied to the scanning line WS1, and then enters the non-conductivestate.

When the write transistor TR_(W) is in the conductive state, the signalvoltage V_(Sig) is written to the gate electrode of the drive transistorTR_(D) through the data line DTL. The gate-source voltage of the drivetransistor TR_(D) during writing is (V_(CC)−V_(Sig)). After the writingis completed, the write transistor TR_(W) enters the non-conductivestate. As a result, the gate electrode of the drive transistor TR_(D)enters the floating state.

By writing the signal voltage, the drain current I_(ds) flows throughthe light-emitting unit ELP, and an anode voltage V_(ANODE) of thelight-emitting unit ELP also rises accordingly. If the amount of rise inthe voltage V_(ANODE) when the light-emitting unit ELP is in the initialstate is represented by a sign V_(A_INI), the amount of rise when thelight-emitting unit ELP after the change with time can be represented as(V_(A_INI)+V_(CWT)).

As described above, after the writing is completed, the gate electrodeof the drive transistor TR_(D) enters the floating state. For thisreason, the change of the anode voltage reaches the gate electrode ofthe drive transistor TR_(D) due to capacitive coupling by thecapacitance C_(GA).

When the light-emitting unit ELP is in the initial state, the amount ofchange of the gate electrode of the drive transistor TR_(D) isrepresented asV _(A_INI) ·C _(GA)/(C _(S) +C _(GA)).

Furthermore, the drain current after the gate voltage change isrepresented asI _(ds) =k·μ·((V _(CC)−(V _(Sig) +V _(A_INI) ·C _(GA)/(C _(S) +C_(GA)))−|Vth|)².

On the other hand, when the light-emitting unit ELP is of after thechange with time, the amount of change of the gate electrode of thedrive transistor TR_(D) is represented as(V _(A_INI) +V _(CWT))·C _(GA)/(C _(S) +C _(GA)).

Furthermore, the drain current after the gate voltage change isrepresented asI _(ds) =k·μ·((V _(CC)−(V _(Sig)+(V _(A_INI) +V _(CWT))·C _(GA)/(C _(S)+C _(GA)))−|V _(th)|)²

Thus, when the initial state is compared with the state after the changewith time, a difference of V_(CWT)·C_(GA)/(C_(S)+C_(GA)) occurs in theamount of change in the gate voltage due to capacitive coupling. As aresult, a difference also occurs in the drain current. Qualitatively, achange occurs such that the drain current decreases due to the changewith time. As a result, the current flowing through the light-emittingunit ELP after the change with time is further reduced, which causes aproblem that the burn-in phenomenon of the display image due to thechange with time of the light-emitting unit ELP is emphasized.

Furthermore, this phenomenon becomes more remarkable as the capacitanceC_(GA) increases as the pixel pitch is reduced.

In the above, the arrangement of the transistors and the problems havebeen described in the drive unit 971 of the reference example.

In the drive unit 71 according to the first embodiment, the capacitancegenerated in the portion where the drive transistor TR_(D) and the writetransistor TR_(W) face each other through the element isolation region22 functions as at least a part of the capacitance unit. As a result,the change in the gate voltage due to capacitive coupling is less likelyto occur.

In the drive unit 71 having the transistor structure illustrated inFIGS. 4 and 5 described above, the capacitance C_(S1) generated in theportion where the drive transistor TR_(D) and the write transistorTR_(W) face each other through the element isolation region 22 isconnected between the first source/drain region 23A of the drivetransistor TR_(D) and the gate electrode of the drive transistor TR_(D).Thus, an equivalent circuit diagram of the display element 70 in thefirst embodiment is expressed as illustrated in FIG. 11. As is clearfrom the connection relationship, the capacitance C_(S1) functions as apart of the capacitance unit. Note that, in a case where the capacitanceC_(S1) has a sufficient capacitance for holding a video signal, thecapacitance C_(S) may be omitted.

In the first embodiment, even if the anode voltage V_(ANODE) duringlight emission changes due to the change with time of the light-emittingunit ELP, the above-described problem due to the capacitive couplingdoes not occur. Thus, it is possible to avoid that the burn-inphenomenon due to the change with time of the voltage-currentcharacteristic (V-I) characteristic of the light-emitting unit of thecurrent drive type is emphasized by the influence of the capacitance.

Depending on the arrangement relationship of the transistorsconstituting the drive unit 71, a shield wiring line may be provided toprevent signal coupling that occurs between wiring lines. To helpunderstanding, first, an arrangement will be described of a shieldwiring line in the drive unit 971 of the reference example describedabove.

FIG. 12 is a schematic plan view for explaining the shield wiring linein the drive unit of the reference example. The arrangement relationshipof the transistors is similar to that in FIG. 6 described above.

In the arrangement of the transistors illustrated in FIG. 6, a wiringpath connecting the second source/drain region 23D of the writetransistor TR_(W) and the gate electrode of the drive transistor TR_(D)to each other intersects with a part to which the anode electrode of thelight-emitting unit ELP is connected. Thus, to prevent the coupling, ithas been necessary to insert a shield wiring line 38 separately asillustrated in FIG. 12.

In the first embodiment, the wiring path connecting the secondsource/drain region 23D of the write transistor TR_(W) and the gateelectrode of the drive transistor TR_(D) to each other intersects with apart to which the feeder line PS1 is connected. Thus, basically, thecoupling can be prevented to some extent even without the shield wiringline.

Furthermore, in the case of more effectively preventing the coupling, asillustrated in FIG. 13, a configuration can also be made in which theshield wiring line 38 is provided around a gate wiring line forconnecting the second source/drain region 23D of the write transistorTR_(W) and the gate electrode of the drive transistor TR_(D) to eachother. By adopting a configuration in which the shield wiring line isconnected to the feeder line PS1, wiring can be simplified. Note that,as illustrated in FIG. 13, the shield wiring line 38 is preferablyrouted to surround the gate wiring line not to generate a capacitancebetween the gate and the anode wiring lines.

In the above, the first embodiment has been described. In the presentdisclosure, the capacitance between the transistors is preferably large.To increase the capacitance, it is effective to increase the junctiondepth of the impurity diffusion layer constituting the transistor. FIG.14 illustrates an example case where the junction depth of the impuritydiffusion layer is made deeper than that in FIG. 5. An impuritydiffusion layer that forms the source/drain region of the drivetransistor TR_(D) and an impurity diffusion layer that forms thesource/drain region of the write transistor TR_(W) are preferably set tohave a junction depth of greater than or equal to 1 micrometer.

In a configuration in which the capacitance is secured by the area ofthe planar layout, the capacitance decreases as the definition becomeshigher. On the other hand, in the configuration of the presentdisclosure in which the capacitance is secured in the vertical directionby the junction depth of the transistor, it is possible to achieve highdefinition while securing the capacitance.

Second Embodiment

A second embodiment relates to a display element, a display device, andan electronic device according to a second aspect of the presentdisclosure.

In the second embodiment, the drive unit further includes a switchingtransistor connected between the feeder line and the first source/drainregion of the drive transistor. The above point is mainly different fromthe first embodiment.

FIG. 15 is a conceptual diagram of a display device according to thesecond embodiment. Note that, for convenience of illustration, FIG. 15illustrates a connection relationship for one display element 270 in adisplay device 2, more specifically, the (n, m)-th display element 270.

In the second embodiment, a drive unit 271 includes a switchingtransistor TR_(S) connected between the feeder line PS1 and the firstsource/drain region 23A of the drive transistor TR_(D). The conductivitytype of the switching transistor is not particularly limited, but theswitching transistor TR_(S) is preferably include a p-channel fieldeffect transistor from a viewpoint of standardization of thesemiconductor manufacturing process. The conductive state/non-conductivestate of the switching transistor TR_(S) is controlled by a signalsupplied to the gate electrode from a light emission control scanner 240via the control line DS1, and for example, operation can be performed ofreducing characteristic variation for each drive unit.

FIG. 16 is a schematic plan view for explaining an arrangement of thetransistors in the drive unit according to the second embodiment.Reference numerals 23E and 23F denote a pair of source/drain regions ofthe switching transistor TR_(S). Also in this arrangement, thecapacitance between the transistors functions as a part of thecapacitance unit.

Third Embodiment

A third embodiment relates to a display element, a display device, andan electronic device according to a third aspect of the presentdisclosure.

In the third embodiment, the drive unit further includes a switchingtransistor connected between the one end of the light-emitting unit andthe second source/drain region of the drive transistor. The above pointis mainly different from the first embodiment.

FIG. 17 is a conceptual diagram of the display device according to thethird embodiment. Note that, for convenience of illustration, FIG. 17illustrates a connection relationship for one display element 370 in adisplay device 3, more specifically, the (n, m)-th display element 370.

In the third embodiment, a drive unit 371 includes a switchingtransistor TR_(M) connected between one end of the light-emitting unitELP and the second source/drain region 23D of the drive transistorTR_(D). The conductivity type of the switching transistor is notparticularly limited, but the switching transistor TR_(M) is preferablya p-channel field effect transistor from the viewpoint ofstandardization of the semiconductor manufacturing process. Theconductive state/non-conductive state of the switching transistor TR_(M)is controlled by a signal supplied to the gate electrode from a lightemission control scanner 340 via the control line EM1, and for example,operation can be performed of reducing characteristic variation for eachdrive unit.

FIG. 18 is a schematic plan view for explaining an arrangement of thetransistors in the drive unit according to the third embodiment.Reference numerals 23G and 23H denote a pair of source/drain regions ofthe switching transistor TR_(M). Also in this arrangement, thecapacitance between the transistors functions as a part of thecapacitance unit.

Electronic Device

The display device of the present disclosure described above can be usedas a display unit (display device) of an electronic device in allfields, the display unit displaying a video signal input to theelectronic device or a video signal generated in the electronic deviceas an image or a video. For example, the display device can be used as adisplay unit of a television set, a digital still camera, a laptoppersonal computer, a mobile terminal device such as a mobile phone, avideo camera, a head mounted display, and the like.

The display device of the present disclosure also includes a moduleshape display device having a sealed configuration. An example is adisplay module in which a facing unit such as transparent glass isattached to a pixel array unit. Note that, the display module may beprovided with a circuit unit for inputting/outputting a signal and thelike to the pixel array unit from the outside, a flexible printedcircuit (FPC), and the like. As a specific example of the electronicdevice using the display device of the present disclosure, a digitalstill camera and a head mounted display will be exemplified below.However, the specific example exemplified here is merely an example, andthe electronic device is not limited to the example.

(Specific Example 1)

FIGS. 19A-B are external views of a lens interchangeable single lensreflex type digital still camera, and FIG. 19A illustrates a front viewof the camera and FIG. 19B illustrates a rear view of the camera. Thelens interchangeable single lens reflex type digital still cameraincludes an interchangeable imaging lens unit (interchangeable lens) 412on the front right side of the camera body part (camera body) 411, andincludes a grip part 413 to be held by an image-capturing person on thefront left side, for example.

Then, a monitor 414 is provided substantially at the center of the rearsurface of the camera body part 411. A viewfinder (eyepiece window) 415is provided on the top of the monitor 414. The image-capturing personcan look in the viewfinder 415, to visually recognize an optical imageof a subject guided from the imaging lens unit 412 and determinecomposition.

In the lens interchangeable single lens reflex type digital still camerawith the above configuration, the display device of the presentdisclosure can be used as the viewfinder 415. That is, the lensinterchangeable single lens reflex type digital still camera accordingto this example is manufactured by using the display device of thepresent disclosure as the viewfinder 415.

(Specific Example 2)

FIG. 20 is an external view of a head mounted display. The head mounteddisplay includes, for example, an ear hooking part 512 for mounting onthe head of a user on both sides of an eyeglass-shaped display unit 511.In this head mounted display, the display device of the presentdisclosure can be used as the display unit 511. That is, the headmounted display according to this example is manufactured by using thedisplay device of the present disclosure as the display unit 511.

(Specific Example 3)

FIG. 21 is an external view of a see-through head mounted display. Asee-through head mounted display 611 includes a body part 612, an arm613, and a lens barrel 614.

The body part 612 is connected to the arm 613 and eyeglasses 600.Specifically, an end portion in a long side direction of the body part612 is coupled to the arm 613, and one side surface of the body part 612is connected to the eyeglasses 600 via a connection member. Note that,the body part 612 may be directly mounted to the head of a human body.

The body part 612 incorporates a control board for controlling operationof the see-through head mounted display 611 and a display unit. The arm613 connects the body part 612 and the lens barrel 614 together, andsupports the lens barrel 614. Specifically, the arm 613 is coupled toeach of the end portion of the body part 612 and an end portion of thelens barrel 614, and fixes the lens barrel 614. Furthermore, the arm 613incorporates a signal line for communicating data related to an imageprovided from the body part 612 to the lens barrel 614.

The lens barrel 614 projects image light provided from the body part 612via the arm 613 toward eyes of a user wearing the see-through headmounted display 611 through an eyepiece. In the see-through head mounteddisplay 611, the display device of the present disclosure can be usedfor the display unit of the body part 612.

Others

Note that, the technology of the present disclosure can also adopt thefollowing configurations.

[A1]

A display element including:

a light-emitting unit of a current drive type; and

a drive unit that drives the light-emitting unit, in which

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

[A2]

The display element according to [A1], in which

the drive transistor and the write transistor are provided in a wellformed in the semiconductor substrate,

the drive transistor includes a first source/drain region to which afeeder line is connected and a second source/drain region connected toone end of the light-emitting unit,

the write transistor includes a first source/drain region to which thesignal voltage is supplied externally and a second source/drain regionconnected to a gate electrode of the drive transistor, and

the second source/drain region of the write transistor and the firstsource/drain region of the drive transistor are formed to face eachother through the element isolation region.

[A3]

The display element according to [A1] or [A2], in which

the element isolation region is formed by a shallow trench isolation(STI) structure in which an insulator is embedded in a groove dug in asurface of the semiconductor substrate.

[A4]

The display element according to any of [A1] to [A3], in which

an impurity diffusion layer that forms a source/drain region of thedrive transistor and an impurity diffusion layer that forms asource/drain region of the write transistor are set to have a junctiondepth of greater than or equal to 1 micrometer.

[A5]

The display element according to any of [A1] to [A4], in which

the drive transistor includes a p-channel field effect transistor.

[A6]

The display element according to any of [A1] to [A5], in which

the write transistor includes a p-channel field effect transistor.

[A7]

The display element according to any of [A2] to [A6], in which

a shield wiring line is provided around a gate wiring line that connectsthe second source/drain region of the write transistor and the gateelectrode of the drive transistor to each other.

[A8]

The display element according to any of [A7], in which

the shield wiring line is connected to the feeder line.

[A9]

The display element according to any of [A2] to [A8], in which

the drive unit further includes a switching transistor connected betweenthe feeder line and the first source/drain region of the drivetransistor.

[A10]

The display element according to any of [A2] to [A8], in which

the drive unit further includes a switching transistor connected betweenthe one end of the light-emitting unit and the second source/drainregion of the drive transistor.

[A11]

The display element according to any of [A1] to [A10], in which

the light-emitting unit includes an organic electroluminescence element.

[B1]

A display device including

display elements arrayed in a two-dimensional matrix, in which

the display elements each include a light-emitting unit of a currentdrive type, and a drive unit that drives the light-emitting unit,

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

[B2]

The display device according to [B1], in which

the drive transistor and the write transistor are provided in a wellformed in the semiconductor substrate,

the drive transistor includes a first source/drain region to which afeeder line is connected and a second source/drain region connected toone end of the light-emitting unit,

the write transistor includes a first source/drain region to which thesignal voltage is supplied externally and a second source/drain regionconnected to a gate electrode of the drive transistor, and

the second source/drain region of the write transistor and the firstsource/drain region of the drive transistor are formed to face eachother through the element isolation region.

[B3]

The display device according to [B1] or [B2], in which

the element isolation region is formed by a shallow trench isolation(STI) structure in which an insulator is embedded in a groove dug in asurface of the semiconductor substrate.

[B4]

The display device according to any of [B1] to [B3], in which

an impurity diffusion layer that forms a source/drain region of thedrive transistor and an impurity diffusion layer that forms asource/drain region of the write transistor are set to have a junctiondepth of greater than or equal to 1 micrometer.

[B5]

The display device according to any of [B1] to [B4], in which

the drive transistor includes a p-channel field effect transistor.

[B6]

The display device according to any of [B1] to [B5], in which

the write transistor includes a p-channel field effect transistor.

[B7]

The display device according to any of [B2] to [B6], in which

a shield wiring line is provided around a gate wiring line that connectsthe second source/drain region of the write transistor and the gateelectrode of the drive transistor to each other.

[B8]

The display device according to any of [B7], in which

the shield wiring line is connected to the feeder line.

[B9]

The display device according to any of [B2] to [B8], in which

the drive unit further includes a switching transistor connected betweenthe feeder line and the first source/drain region of the drivetransistor.

[B10]

The display device according to any of [B2] to [B8], in which

the drive unit further includes a switching transistor connected betweenthe one end of the light-emitting unit and the second source/drainregion of the drive transistor.

[B11]

The display device according to any of [B1] to [B10], in which

the light-emitting unit includes an organic electroluminescence element.

[C1]

An electronic device including

a display device including display elements arrayed in a two-dimensionalmatrix, in which

the display elements each include a light-emitting unit of a currentdrive type, and a drive unit that drives the light-emitting unit,

the drive unit includes a capacitance unit, a drive transistor thatcauses a current corresponding to a voltage held by the capacitance unitto flow through the light-emitting unit, and a write transistor thatwrites a signal voltage to the capacitance unit,

the drive transistor and the write transistor are formed in a state ofbeing separated by an element isolation region, on a semiconductorsubstrate, and

a capacitance generated in a portion where the drive transistor and thewrite transistor face each other through the element isolation regionfunctions as at least a part of the capacitance unit.

[C2]

The electronic device according to [C1], in which

the drive transistor and the write transistor are provided in a wellformed in the semiconductor substrate,

the drive transistor includes a first source/drain region to which afeeder line is connected and a second source/drain region connected toone end of the light-emitting unit,

the write transistor includes a first source/drain region to which thesignal voltage is supplied externally and a second source/drain regionconnected to a gate electrode of the drive transistor, and

the second source/drain region of the write transistor and the firstsource/drain region of the drive transistor are formed to face eachother through the element isolation region.

[C3]

The electronic device according to [C1] or [C2], in which

the element isolation region is formed by a shallow trench isolation(STI) structure in which an insulator is embedded in a groove dug in asurface of the semiconductor substrate.

[C4]

The electronic device according to any of [C1] to [C3], in which

an impurity diffusion layer that forms a source/drain region of thedrive transistor and an impurity diffusion layer that forms asource/drain region of the write transistor are set to have a junctiondepth of greater than or equal to 1 micrometer.

[C5]

The electronic device according to any of [C1] to [C4], in which

the drive transistor includes a p-channel field effect transistor.

[C6]

The electronic device according to any of [C1] to [C5], in which

the write transistor includes a p-channel field effect transistor.

[C7]

The electronic device according to any of [C2] to [C6], in which

a shield wiring line is provided around a gate wiring line that connectsthe second source/drain region of the write transistor and the gateelectrode of the drive transistor to each other.

[C8]

The electronic device according to any of [C7], in which

the shield wiring line is connected to the feeder line.

[C9]

The electronic device according to any of [C2] to [C8], in which

the drive unit further includes a switching transistor connected betweenthe feeder line and the first source/drain region of the drivetransistor.

[C10]

The electronic device according to any of [C2] to [C8], in which

the drive unit further includes a switching transistor connected betweenthe one end of the light-emitting unit and the second source/drainregion of the drive transistor.

[C11]

The electronic device according to any of [C1] to [C10], in which

the light-emitting unit includes an organic electroluminescence element.

REFERENCE SIGNS LIST

1, 2, 3, 9 Display device

10 Base material

20 Semiconductor layer

21 N well

22 Element isolation region

23A, 23B, 23C, 23D, 23E, 23F, 23G, 23H Source/drain region

31 Gate insulating layer

31′ Insulating layer

32 Gate electrode

32′ Second electrode

33 Interlayer insulating layer

34 First electrode

35, 36 Contact hole

37 Wiring line

38 Shield wiring line

40 Interlayer insulating layer

51 Anode electrode

52 Hole transporting layer, light emitting layer, and electrontransporting layer

53 Cathode electrode

54 Second interlayer insulating layer

55, 56 Contact hole

60 Transparent substrate

70, 270, 370, 970 Display element

71, 271, 371, 971 Drive unit

80 Display area

100 Semiconductor substrate

110 Source driver

120 Power supply unit

130 Vertical scanner

240, 340 Light emission control scanner

TR_(W) Write transistor

TR_(D) Drive transistor

C_(S) Capacitance unit

ELP Organic electroluminescence light-emitting unit

C_(EL) Capacitance of light-emitting unit ELP

C_(GA) Capacitance of reference example

C_(S1) Capacitance

TR_(S), TR_(M) Switching transistor

WS1 Scanning line

DTL Data line

PS1 Feeder line

PS2 Common feeder line

DS1, ME1 Control line

411 Camera body part

412 Imaging lens unit

413 Grip part

414 Monitor

415 Viewfinder

511 Eyeglass-shaped display unit

512 Ear hooking part

600 Eyeglasses

611 See-through head mounted display

612 Body part

613 Arm

614 Lens barrel

The invention claimed is:
 1. A display device comprising: a lightemitting element; a capacitive component; a sampling transistorconfigured to supply a data signal voltage from a data signal line tothe capacitive component; and a driving transistor configured to supplya driving current to the light emitting element according to a voltagestored in the capacitive component, wherein the capacitive componentincludes a first capacitor and a second capacitor electrically connectedin parallel with the first capacitor, a first end of the capacitivecomponent is electrically connected to a gate electrode of the drivingtransistor, and a second end of the capacitive component is electricallyconnected to a first voltage line.
 2. The display device according toclaim 1, wherein the first end of the capacitive component iselectrically directly connected to the gate electrode of the drivingtransistor, and the second end of the capacitive component iselectrically directly connected to the first voltage line.
 3. Thedisplay device according to claim 1, wherein a first source/drain regionof the driving transistor is electrically connected to the first voltageline.
 4. The display device according to claim 1, wherein the firstvoltage line is configured to supply a constant voltage to the drivingtransistor.
 5. The display device according to claim 1, furthercomprising a switching transistor electrically connected between thedriving transistor and the light emitting element.
 6. The display deviceaccording to claim 1, wherein the driving transistor is a n-channel typetransistor.
 7. The display device according to claim 1, wherein thefirst capacitor is formed in a first layer and the second capacitor isformed in a second layer.
 8. The display device according to claim 7,wherein, in a cross-sectional view, the first layer is higher than thesecond layer.
 9. The display device according to claim 1, wherein afirst electrode of the first capacitor is the gate electrode of thedriving transistor or an electrode formed on a same layer as the gateelectrode of the driving transistor.
 10. The display device according toclaim 1, wherein the first capacitor is a MIM (Metal-Insulator-Metal)capacitor.
 11. The display device according to claim 1, wherein anisolation region is formed between a semiconductor region of the drivingtransistor and a semiconductor region of the sampling transistor. 12.The display device according to claim 11, wherein the isolation regionis formed by a shallow trench isolation structure in which an insulatoris embedded in a groove that extends into a surface of a semiconductorsubstrate.